According to Ken McCarthy, Cushman & Wakefield’s New York-area research chief, the average Manhattan office building asking rent increased in February by 2 cents per square foot over the month before. Before you laugh, know that the puny uptick represents the first time the “ask” has gone up since September 2008, better known as The World Before Lehman Fell.

What’s it mean? “The market now appears to be bottoming,” McCarthy said, after its Homeric-scale collapse since 2008.

Of course, the “ask” matters less than “taking” rents, and even less than net-effective rents — what a lease actually costs a tenant after landlord concessions such as work-letters and free-rent periods are taken into account. But that measure, too, finally has stabilized after 18 months in free fall.

In the first quarter of 2008, Manhattan net-effective rents averaged $69.48 a square foot, according to Cushman. By the third quarter of 2009, they’d fallen to $42.89 — a staggering, 38.3 percent decline.

But the net-effective number might have found its floor, too.

McCarthy said the average inched up to $43.95 in the fourth quarter last year. The question remains: Does recent stabilization augur a return to better times, or is it merely a case of an ongoing collapse catching its breath before plunging further?

Recent adventures in net-effective rent slashing have been the talk of the city’s buzzy leasing world.

As we reported in January, Avon Product’s 15-year, 246,500-square- foot lease at 777 Third Ave., starting in the low $40s per square foot and rising into the low $50s over time, included a year’s free rent. If the average rent were $45 a foot over the term, the free-rent year would reduce Avon’s actual cost to about $42 a foot.

Last summer, The Wall Street Journal reported that law firm Orrick Herrington & Sutcliffe was paying in the $70s per square foot for 220,000 square feet at 51 W. 52nd St.

Not only was that 40 percent less than it might have cost one year earlier, but landlord CBS paid for the law firm’s buildout to the tune of $150 a square foot.

The catastrophic fall in net-effective rent not only dented landlords’ bottom lines, it added more instability to the reeling investment-sale market.

The main reason large properties are not trading, of course, is the unavailability of credit.

Banks have many reasons for not wanting to lend — but it hasn’t helped that plummeting rent revenue made it impossible to place a value on even the best buildings.

McCarthy said, “A year ago, nobody knew what rent to charge. There was very little leasing activity. We were losing 600,000 jobs a month nationally.

“Then we hit a point in midyear when businesses found they were going to survive after all. Rents were cheap, some companies needed space, and net-effective rents stopped falling.”

Despite the apparent sign of health, overall Manhattan vacancy continues to creep up — by Cushman’s data, to about 11.3 percent today, compared with 9.1 percent one year ago and — remember? — 5.8 percent in February 2008.

CB Richard Ellis’ Global Leasing Director Stephen B. Siegel, is known as an optimist. But his upbeat take on current trends is persuasive. “Leasing velocity has been nothing short of spectacular since the end of last May,” he said.

Siegel said CBRE’s Manhattan leasing has been nearly double the 900,000 square feet a month it did in the first five months of 2009.

Acknowledging that all the activity has not yet reduced overall vacancy or forced rents significantly upward, Siegel said, “Ultimately, it will increase positive absorption.”

He cited recent deals that were pure expansion — such as at 120 W. 45th St., where DE Shaw Research went from 30,000 to 75,000 square feet.

The only thing that will definitively turn the market around, McCarthy said, is significant job growth — which seems a distant prospect even though city job losses blamed on the recession are now estimated at 200,000 rather than a feared 300,000, and 30,000 financial- sector job losses to date are only half of the most dire predic tions.

Some financial firms are actually hiring. But mod est upticks in jobs don’t imme diately translate into more demand for space.

In fact, many of the most publicized, large, newly signed leases recently have resulted in greater space availability as companies consolidate functions from several locations into a single address. We’ll be watching for the next 2 cents. steve.cuozzo@nypost.com